Search results for "Bacteria"
showing 10 items of 4919 documents
A polyphasic approach in order to identify dominant lactic acid bacteria during pasta manufacturing
2010
Using a polyphasic approach, we have isolated and identified, lactic acid bacteria (LAB) in samples directly collected from an artisanal pasta-making manufactory located in Puglia (South Italy). Samples were collected during several steps of pasta processing and LAB were isolated on MRS and M17 plates. Furthermore, strains were grouped in a total of eight species by means of randomly amplified polymorphic DNA (RAPD)-polymerase chain reaction (PCR) typing and 16S rDNA sequencing. The majority of strains were identified as belonging to Pediococcus pentosaceus and Enterococcus faecium species. The remaining strains were characterized and assigned to Weissella confusa, Pediococcus acidilactici,…
Purification and molecular characterization of the rhamnose binding lectin from sea bass (Dicentrarchus labrax) that agglutinate Gram positive and ne…
2013
Kinetic Characterization of Secretory Transport of a New Ciprofloxacin Derivative (CNV97100) across Caco-2 Cell Monolayers**This work has been submit…
2002
The kinetics of transport of a new fluoroquinolone antibiotic (CNV97100) and its analogs were characterized using the Caco-2 cell culture model. Unidirectional permeabilities of these analogs were greater (p < 0.05) than that of ciprofloxacin. The absorptive permeabilities (P(AB)) of 4'-N-substituted analogs (CNV97101-104) were 400-600% greater, whereas the secretory permeability (P(BA)) was 25-80% greater than unsubstituted analogs because CNV97101-104 were poor substrates for efflux transporters (efflux ratio approximately 1). The transport of compounds without 4'-N-substitution (i.e., ciprofloxacin and CNV97100) favored secretion (efflux ratio approximately 4). Further characterization o…
Mechanism of lipid-body formation in prokaryotes: how bacteria fatten up
2004
Neutral lipid accumulation is frequently observed in some Gram-negative prokaryotes like Acinetobacter sp. and most actinomycetes, including the pathogenic Mycobacterium tuberculosis and antibiotic producing streptomycetes. We examined the formation of wax ester- and triacylglycerol (TAG)-bodies in Acinetobacter calcoaceticus and Rhodococcus opacus using microscopic, immunological and biophysical methods. A general model for prokaryotic lipid-body formation is proposed, clearly differing from the current models for the formation of lipid inclusions in eukaryotes and of poly(hydroxyalkanoic acid) (PHA) inclusions in prokaryotes. Formation of lipid-bodies starts with the docking of wax ester …
Differences in Attachment and Phagocytosis of Salmonella minnesota Strains (S Form, Re Mutant) by Mouse Peritoneal Macrophages: Participation of Endo…
1985
The virulence of bacteria in many phagocytic systems has been studied for several years and it is known that macrophages play an important role in host defence against invading microorganisms and in cooperation with cellular and humoral immune mechanisms. Pathogenic bacteria can be divided into two groups with regard to their fate within phagocytes: (a) extracellular bacteria which are promptly killed after phagocytosis and (b) facultative intracellular bacteria which are resistant to intracellular killing unless macrophages are activated. Humoral immune mechanisms (antibody, complement) deal mainly with extracellular bacteria, while cellular immune mechanisms (T cells, macrophages) deal wi…
Differential enumeration and in situ localization of microorganisms in the hindgut of the lower termite Mastotermes darwiniensis by hybridization wit…
1999
We examined the abundance and spatial distribution of major phylogenetic groups of the domain Bacteria in hindguts of the Australian lower termite Mastotermes darwiniensis by using in situ hybridization with group-specific, fluorescently labeled, rRNA-targeted oligonucleotide probes. Between 32.0 +/- 7.2% and 52.3 +/- 8.2% of the DAPI-stained cells in different hindgut fractions were detected with probe EUB338, specific for members of the domain Bacteria. About 85% of the prokaryotic cells were associated with the flagellates of the thin-walled anterior region (P3a) and the thick wall of the posterior region (P3b/P4) of the hindgut, as shown by DAPI staining. At most, half of the EUB338-det…
Metagenomic Analysis of Milk of Healthy and Mastitis-Suffering Women.
2015
Background: Some studies have been conducted to assess the composition of the bacterial communities inhabiting human milk, but they did not evaluate the presence of other microorganisms, such as fungi, archaea, protozoa, or viruses. Objective: This study aimed to compare the metagenome of human milk samples provided by healthy and mastitis-suffering women. Methods: DNA was isolated from human milk samples collected from 10 healthy women and 10 women with symptoms of lactational mastitis. Shotgun libraries from total extracted DNA were constructed and the libraries were sequenced by 454 pyrosequencing. Results: The amount of human DNA sequences was ≥ 90% in all the samples. Among the bacteri…
Characterization of Lactobacillus isolates from fermented olives and their bacteriocin gene profiles
2011
Near one hundred isolates of Lactobacillus paraplantarum, Lactobacillus pentosus and Lactobacillus plantarum from table olives were studied. Strains were genotyped by rep-PCR. Although the technique failed to differentiate some isolates at the species level, it proved a robust and easy procedure that could be useful for distinguishing between related strains of L. paraplantarum, L. pentosus and L. plantarum from a large pool of unrelated strains of these species. A PCR-based screening revealed the presence of the plantaricin encoding genes plnA, plnB, plnC, plnD, plnE/F, plnF, plnI, plnJ, plnK, plnG and plnN in most isolates of the three species. Sequences of bacteriocin genes present in L.…
Composition and Antimicrobial Activity of Essential Oil ofAnthemis tenuisectaBall
2007
Abstract The Chemical composition of the essential oil of Anthemis tenuisecta Ball. (Anthemideae) was analyzed by gas Chromatography-mass spectrometry (GC-MS). Forty eight components accounting for 89.5 % of the oil were identified, being camphor (17.5 %), 6-methyl-5-hepten-2-one (17.1 %), borneol (11.5 %), sesquicineole (11%) and camphene (5.7 %) the main compounds. In the antibacterial diffusion assay, the oil showed activity against Gram-positive bacteria.
Composition and Antibacterial Activity of Essential Oils ofCladanthus arabicusCass. (Asteraceae)
2005
Abstract The chemical composition of the essential oils of the aerial parts (stems and leaves: sample A) and flowers (sample B) of Cladanthus arabicus Cass., were analysed by GC-MS. Monoterpenes hydrocarbons constituted the main chemical group in both essential oils, with Sabinene, β-pinene, α-pinene, myrcene, α-phellandrene and p-cymene as the main compounds. Sample A was tested for its antimicrobial activity against six Gram positive and negative bacteria. Results showed that the oil exhibited a significant antibacterial activity.